Inversion forms tall or flat Alaska Range mirage

Posted: Tuesday, January 18, 2011

FAIRBANKS — A temperature inversion provided some different views of the Alaska Range last week, making the mountains look a little taller or flatter with an illusion named after a legendary sorceress.

The Fairbanks Daily News-Miner reports the atmospheric illusion is known as a “superior mirage” and is informally called a Fata Morgana — the Italian name for Morgan le Fay, the sorceress who tormented King Arthur.

The mirage is fairly common in Fairbanks, where conditions are often just right. It requires a local temperature inversion — a layer of cool air beneath warmer air — and the windless, cloudless conditions that prevail in the Tanana Valley.

The Alaska Range often appears taller under those conditions. But it can also make things look a little flatter, or stretched out.